It is known in a power-driven tacker to mount the staple magazine to be movable between a blocking position and an operating position. In the blocking position, the magazine outlet end for the staples is pivoted downwards away from the tacker housing. In the operating position, the outlet end of the magazine is pivoted upwards into a position adjacent the tacker housing.
German Utility Model No. 8,303,460 discloses such an electro-magnetic tacker in which the actuator element of the main switch is connected to an elongate coupling element which extends downwards to just above the staple magazine. In the blocking position of the staple magazine, a blocking element fastened pivotably to the housing engages into a locking recess in the elongate coupling member. When the staple magazine is pivoted into the operating position, the blocking element pivots as a result, so that the coupling element is released and the actuator element can be displaced to actuate the main switch. The tacker carries out a driving stroke only when the staple magazine is in its operating position, that is to say when the outlet of the staple output channel is placed on a workpiece. The tacker is electronically controlled, and carries out a driving stroke whenever the actuator element is actuated. To execute a further driving stroke, the tacker has to be lifted off from the workpiece and replaced, whereupon a further staple is driven into the workpiece by means of the following driving stroke.
German Offenlegungsschrift No. 2,823,248 discloses a tacker which is controlled by electronics and which, when the main switch is actuated, carries out a specific number of driving strokes, but more than one stroke so that a staple or a nail can be driven even into a relatively hard workpiece. For this purpose, the actuator element of the main switch has coupled to it a staple blocking means which is displaced as a result of actuation of the actuator element, in such a way that it prevents the front staple or the front nail from subsequently being transferred from the staple magazine into the staple output channel. Thus, the driver strikes the same staple or the same nail several times, without further staples or nails being fed into the staple output channel. To start a new operating cycle, the actuator element of the main switch must be released, as a result of which the staple blocking means releases the front staple or the front nail from the staple magazine so that it then enters the staple output channel. When the actuator element is actuated again, a further sequence of driving strokes can be triggered.
French Patent Specification No. 1,290,830 discloses a tacker in which the number of driving strokes is controlled as a function of the driving depth which is reached. For this purpose, this tacker too has a staple blocking means which is connected to the actuator element of the main switch and which, during a cycle of driving strokes, prevents a staple or a nail from being conveyed out of the staple magazine into the staple output channel. When the main switch of the tacker supplied with direct-current voltage is closed, successive driving strokes are triggered. When the predetermined driving depth is reached, an angle fastened to the drive-solenoid armature connected firmly to the driver engages with a toggle lever mounted pivotably on the actuator element and pivots this toggle lever in such a way that the main switch is opened. It is possible to reclose the main switch by actuating the actuator element only after the latter has been released and thus, as a result of the release of the staple blocking means, a new staple or a new nail has been transported into the staple output channel.